Conventional tire pressure management systems typically have central tire inflation systems (CTI systems), also known as on-board inflation systems and traction systems. These tire pressure management systems are well known, as may be seen by reference to the following U.S. Pat. Nos.: 5,516,379; 5,313,995; 5,273,064; 5,253,687; 5,180,456; 5,179,981; 5,174,839; 5,121,774; 4,924,926; 4,992,946; 4,917,163; 4,893,664; 4,883,106; 4,883,105; 4,825,925; 4,782,879; 4,754,792; 4,724,879; 4,678,017; 4,640,331; and 4,619,303. The entire disclosures of each of these patents is incorporated herein.
Generally, tire pressure management systems employ a pneumatically controlled wheel valve that is affixed to each vehicle wheel assembly for controlling tire pressure in response to pressure signals from a fluid control circuit. The fluid control circuit is connected to each wheel valve via a rotary seal assembly associated with each wheel valve. Tire pressure may be monitored by a sensor positioned in a conduit assembly in the fluid control circuit. When the wheel valve and certain control valves are opened, the pressure in the conduit assembly equalizes to tire pressure which can be sensed by the sensor. An electronic control unit receives electrical pressure signals generated by the sensor and appropriately controls the fluid control circuit in response thereto for inflating or deflating a selected tire.
Most tire pressure management systems rely on multiple solenoids for promoting and prohibiting flow with respect to a fluid source or sink, and for promoting and prohibiting flow with respect to tires and/or tire sets. Many of these tire pressure management systems also rely on multiple pressure sensors for ascertaining fluid pressures associated with fluid sources, tires and the various conduit assemblies therebetween. For example, one sensor may be dedicated to sensing the pressure of fluid in the fluid source, while another sensor may be dedicated to sensing the pressure of fluid in a tire.
The use of multiple sensors is costly and may respond to pressure differently, thus potentially causing a tire pressure management system to undertake certain operations based on pressure measurements that to not comport with other pressure measurements. To enjoy the advantages provided through implementation of a centralized sensor configuration, tire pressure management systems typically require the use of multiple valves or solenoids to effect fluid communication between the sensor and the element, such as the fluid source or a tire, for Which pressure measurement is needed. Coordination of multiple valves is cumbersome, generating and potentially problematic. What is needed is an apparatus for and a method of sensing fluid pressure of a tire and the fluid supply of a tire pressure management system maintaining same, with a central sensor and which requires the control of only two valves.